When a child becomes too big to sit in an infant's car seat installed in a vehicle, the child is placed directly in a seat. Vehicle seats, however, are generally designed for adults. Consequently, the seating surface is often too long for only the child's thighs to rest on the seat when the child's back is braced against the seat back. The seat pan extends partially beneath the child's legs and the feet are not supported. This position is obviously uncomfortable for the child.
Document DE 44 12 617 describes a seat in which a front section of the seat pan pivots downward. The fixed part of the seat pan is thus sufficiently short for the child to be able to bend his/her knees. The child's feet are then in contact with a surface of the mobile part of the seat pan. When the mobile part is in the raised position, the seat pan supports the thighs of an adult in the normal fashion.
However, when the mobile part pivots, it occupies a space that extends beyond that normally occupied by the seat, and is exposed to bumps, particularly from the occupant's feet.